Method of forming circular t-section tracks from straight pieces of rail.



A. 0. MOSBY. METHOD OF'FORMING CIRCULAR T-SECTION TRACKS FROM STHA-GHTPIECES OF RA|L.'

APPLICATION FILED MAY 31. 1911.

Patented June 18, 1918.

2-SHEETSSHEET I.

villa MW A. D. MOSBY. ULAR T-SECTION TRACKS FROM STRAIGHT PIECES OFRAIL.

METHOD or FORMING cmc I APPLICATION FILED MAY 31. 1911.

1,269,631. PatentedJunexl8, 191s.

2 3HEETS$H EET 2.

llllllll'llllllllll ll ALFRED D. MOSIBY, 0F CHICAGQILLINOIS, ASSIGNOR TOMARSH-OAPRON MANUFAC- TUBING COMPANY, OF CHICAGO, ILLINOIS, ACORPORATION OF ILLINOIS.

METHOD OF FORMING CIRCULAR T-SECTION TRACKS FROM STRAIGHT vPIECES, OFRAIL.

Specification of Letters Patent.

Application filed May 31, 1911. Serial No. 630,283.

To all whom it may concern:

Be it known that I, ALFRED D. MOSBY, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Methods of FormingCircular T-Section Tracks from Straight Pieces of Rail, of which thefollowing is a specification.

My invention relates to an improvement in circular tracks or tires,suitable for use upon the revolving drums of concrete mixers, or uponother drums or revolving elements of apparatus of similar character; andthe object of the invention is to provide an improved steel T-sectiontrack or tire together with a novel method of forming the same from astraight piece of T' section rail road rail of the ordinary sort. Themethod consists in taking a piece of common T section rail and causingit, while cold, to be moved back and forth between three bearing orpressure exerting elements, for example, rollers, which are arranged tobear and exert pressure against the upper and lower surfaces of therail, two on-one side and the third between the other two on theopposite side of the rail, and gradually either by a constant movementor by a succession of movements repeated at suitable intervals, shiftingone or more of said rolls in the direction of the opposed roller orrollers so as to continue or reestablish the pressure as it is relievedby the bending of the rail. In this way, the web and ball of the railare stretched, the base flange bent, and the whole rail gradually givenacurved configuration. As the forming rollers are necessarily spacedapart so that it is impossible to give the end portions of the rail acurved configuration, the method preferably involves imparting to therail a spiral bend which oflsets its opposite ends and proceeding withthe bending operation until the substantially straight portions at theextremities of the rail are overlapped, then cutting off these portions,springing the ends into alinement and securing them together.

. The method is best illustrated by reference to the accompanyingdrawings, which show, in a diagrammatic manner, apparatus ther show theoperation concerned at Various diiferent stages. In the drawings- Figure1 is a longitudinal sectional elevation of the forming rollers;

Fig. 2, a sectional View taken on line 22 of Fig. 1, looking in thedirection of the arrows, and on a somewhat enlarged scale;

Fig. 3, an edge view of the circular track before the straight portionsat its ends have been cut ofi Fig. 4, a cross-section of the track, theoriginal shape of the rail being indicated approximately by the dottedlines;

gig. 5, a side view of the finished track; an

Fig. 6, a view in elevation, with parts in section, of the drum of aconcrete mixer, showing the application thereto of the circular track.

Like characters of reference indicate like parts in the several figuresof the drawings.

A, B and (J designate the three bearing elements or rollers. Roller Abears against the normally under side of the base flange of the rail,the rail being designated D. The roll is preferably formed with theshallow groove a for the purpose of preventing the rail from slipping onthe roller. Rollers B and C are preferably alike. Referring particularlyto Fig. 2, the roller B is shown as formed with a deep groove 6 whichreceives the web and the ball of the rail, the ball bearing against acore 6. The side members 6 b", of the roller bear against the normallyupper surfaces of the base flange of the rail and the perimeters insteadof being beveled in conformity to the slope of the upper sides of thebase flange are formed on lines parallel to the axis of the roller sothat in the finished track the base flanges are flattened, as indicatedat (Z, (Fig. 4). In order to accomplish this result the effectivebearing of the rail on the lower rollers must necessarily be between thebase flange and the elements 6 and not between the tread or uppersurface of the ball of the rail and the element 6. The ball of the rail,for example, may initially stand out of contact with the element 6 or,even if it touches it in some cases, the stretching of the ball andPatented June 18, 1918.

the web, which takes place when the rail is bent from the straight formto the circular form, will diminish the height of the web and ballsufficiently so that the eflective bearing is still maintained at thebase flange of the rail. This disposition of the rail with regard to thelower rollers is important apart from the fact that it allows theswaging or flattening of the base flange in that it permits the web andball to stretch freely. This circumstance, taken with the fact that theball is guided at the sides, as is preferably also the base flange,makes it possible to bend this diflicult cross section by a cold processwithout distorting the relatively thin web and base flange. It will beunderstood that it is difficult to bend a straight piece of T sectionrailroad rail into circular form with the ball outward because of thevery considerable mass of metal in the ball, where the greatest amountof stretching has to take place, in comparison with the lightness of thebase flange and of the connecting web. In fact, up to the time that myinvention was perfected it had been generally considered impossible toperform this operation without getting a distortion of the rail whichwould make the finished article impractical for the purpose to which thetracks or tires turned out by my process are used.

This flattening of the base flanges facilitates the attachment of thetrack to the drum by providing a right angle surface instead of asloping surface to drill against. The boxes E in which roller B isjournaled are adj ustably mounted so that the roller may be shifted,either by constant or intermittent movements, from the position shown inthe full lines of Fig. 1 to that indicated by the dotted lines; that is,as the pressure exerted by the rollers against the rail is relieved bythe bending of the rail it is reestablished by shifting the position ofroller B. Obviously, the same results might be obtained by shiftingeither of the other two rollers, or, if desired, more than one rollermight be shifted. As above stated, the rollers by bearing against theupper inclined surfaces of the base flange cut into the same. Thisoperation besides flattening the outer margins of the base flange hasthe further result of assisting in holding the rail against lateraldisplacement. The stresses tending to distort the rail are, of course,the greatest as the curvature of the rail approaches circularity. Bythis time shoulders have been formed by the flattening process whichmaterially aid in checking the tendency of the rail to distort.

During this operation a lateral pressure is exerted upon the rail,either by hand or by suitable apparatus, which offsets the ends of therail. In effect, the rail is given a spiral rather than a strictlycircular curvature. This enables the straight portions at the ends ofthe rail to be overlapped as indicated in Fig. 3, the bending operationbeing carried on until this overlapping occurs and until a curvature ofthe desired radius is produced. The overlapping, straight portions atthe extremities of the rail are then cut off, for example, on the lineof Fig. '3, and the ends of the circular structure which results sprunginto alinement with each other and secured together by the fish-plate d,as shown in Fig. 5.

Fig. 6 shows the application of a pair of tracks so formed to the drumof a concrete mixer. F designates the drum and G, G the flanged wheelson which it is supported and revolved. The tracks D are slipped over thedrum and rivet holes d drilled through the base flanges of the track andat the same time through the drum. d designates the rivets. Theoperation of drilling the rivet holes is facilitated by the fact thatthe base flanges have been flattened in the bending operation as abovedescribed.

A great deal of difliculty has been experienced in providing therevoluble drums of concrete mixers with tracks or tires which will notbecome soon worn out or damaged. Where such tracks or tires are formedintegrally with the body of the drum it is necessary to throw away thedrum when the tracks wear out. Ordinary cast rings secured to the drumare not satisfactory because they wear out quickly and because it is notalways easy to get a good flt of the rings on the drum. The liability ofrings or tracks of this sort to Wear is enhanced by the fact that waterand cement from the interior of the drum are apt to slop out of thecharging and discharge openings, trickle around the edge of the drum andso get in between the track and the wheels or rollers on which it bears.My method makes it possible to provide the drums of concrete mixers witha very durable track made of hard steel which will under ordinarycircumstances outlast the life of the drum itself. If, however, thetrack should become worn or damaged it may be easily removed and anotherput in its place. The T section configuration of the track is such as tointercept in the spaces under the ball of the rail any slop which maytrickle around the end of the drum and so prevent it from coming betweenthe bearing surfaces of the track and rollers on which it is supported.

The method above described provides a bearing ring which is superior toa cast metal ring in that it will not have any of the flaws orweaknesses that a casting of this diameter would be very likely to have.In the first place, the rail from which the ring is formed consists ofrolled metal which for that reason is stronger than cast steel would be,the rolling giving a grain or texture to the metal which adds to itsstrength. If the original rail should contain any flaw or weakness itwill not be able to withstand the stresses developed during the coldbending process. The cold bending process gives an article much superiorto one produced by a hot bending process in which the rail is reheated,if such process were possible with a section of this sort, because thereheating of the rail necessarily reduces its carbon. By my process therail is stretched without changing the chemical character of the metal.

I claim:

1. The method of forming from a straight piece of T section railroadrail a circular bearing ring having the ball of the rail on the outsideand the base flange on the inside which consists in causing the railwhile cold to be moved back and forth between bearing elements whichexert bending pressures only against the rail base while guiding theball of the rail so as to hold it from lateral displacement.

2. The method of forming from a straight piece of T section railroadrail a circular bearing ring having the ball of the rail on the outsideand the base flange on the in side which consists in causing the railWhile cold to be-moved back and forth between bearing elements whichexert bending pressures only against the rail base while guiding thesides of the ball of the rail, and also the edges of the rail base, soas to hold them from lateral displacement.

3. The method of forming a circular track or tire of the characterdescribed from a straight piece of T-section railroad rail by a coldbending operation which consists in causing the rail to be moved backand forth between bearing elements arranged to exert bending pressuresagainst opposite sides of the rail base while guiding the ball of therail so as to hold the same from lateral displacement, exerting saidbending pressures so as to give the rail a slight helical form,continuing the operation until the straight ends of the rail areoverlapped and the track brought to the proper diameter, and thencutting ofi the overlapping portions.

4:. The method of forming a circular track or tire of the characterdescribed from a straight piece of T-section railroad rail by a coldbending operation which consists in causing the rail to be moved backand forth between bearing elements which exert pressure against thebottom of the rail base and elements which exert pressure against theupper inclined surfaces of the rail base, the latter so formed as to cutinto the same While guiding the ball of the rail so as to hold it fromlateral displacement.

ALFRED D. MOSBY. Witnesses:

P. H. TRUMAN, L. A. FALKENBERG.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

